Don't know what to do...

Okay... this is not meant to be rude, but I'm guessing you're pretty young. Most young people have that fear of psych and dementia patients, and it's 100% stereotyping and not understanding their mental process. Allowing yourself to see them as anything other than just people is an epidemic in our society and is what keeps the stigma in place in mental health care.

I've always been in Med/Surg, and I'm pretty used to dealing with psych and dementia patients. You need to realize that they're just people, and normally, they need our care the most. If you're really that terrified of them, you need to spend more time with them, and you also need to see that just about everyone is a psych patient when they're in the hospital. Being sick or injured brings out the worst in people, and you need to show greater compassion and understanding, especially when they have histories that make it harder on them to adapt in crisis situations.

Sit with them. Talk to them like you'd talk to any other patient. Hold their hand. Get to know them. See them for who they really are. I once sat for an hour with a patient who had very severe schizophrenia, was self medicating with heroin, and wouldn't talk to anyone. This led a lot of the staff to be afraid of him, especially because he looked dirty and homeless. Turns out he just didn't feel like anyone cared, and when someone showed real interest he opened up and told me his whole life story. It was a honor to be trusted, and that's the type of attitude you need to take. People are people, even if they're 80 years old and have no idea what's going on. I kinda love dementia patients, because they tell the best stories and don't remember you poked them with a gigantic needle five minutes ago.

Bottom line... you can do this. You can do hard things. Tell yourself that. Stop being afraid. Let yourself get to know patients, and treat them how you'd want to be treated.

Maybe the fact that you're pregnant is contributing to your fears? I was pregnant in nursing school and was terrified of psych patients. I think it's a protective mechanism. Be kind to yourself and baby and always put yourself first. Listen to your instincts and ask for help. Best wishes to you and your baby :)